By Tom Ashby LAGOS, Jan 17 (Reuters) - An armed attack on an oil industry boat in Nigeria's southern Niger Delta on Tuesday in which a Dutch worker and Nigerian serviceman were killed was a robbery, industry and security sources said on Wednesday. A senior foreign oil industry executive said the attack was symptomatic of a descent into anarchy in Africa's oil heartland. The two men were shot dead when 16 gunmen ambushed a small ferry operated by South Korean firm Hyundai on a river between regional capital Port Harcourt and the Bonny Island oil and gas complex, the Korean Foreign Ministry said. Six others were wounded. "The motive of the attack was to steal a large sum of money in the boat," a military source said, adding that it was likely that information about the transport of funds had been leaked from inside Hyundai. "I am sure we will catch those behind it," said the source, who did not wish to be named. Violence is intensifying in the Niger Delta, home to Africa's biggest oil industry, and has already cut output by a fifth and forced thousands of foreign workers to leave. Police and navy spokesmen declined to comment on the attack. Foreign oil workers are rarely killed in the delta, although they are often kidnapped for ransom or by militants pushing for greater regional autonomy. "I think we will see more of this over the next few months. Less integration, more anarchy," said a senior oil industry executive. Many analysts expect violence to escalate across Nigeria in the run-up to a general election in April, especially in the delta where political office comes with control over a big slice of the nation's oil revenue. Hyundai is building oil storage tanks and offices for Royal Dutch Shell <RDSa.L> at the Bonny Island complex, which exports 400,000 barrels a day of crude oil and 20 million tonnes a year of liquefied natural gas. COMMUNAL CONFLICT The attack was apparently unrelated to a spiralling communal conflict at a nearby community in Rivers state where 12 people were killed on Sunday, prompting oil companies to evacuate three oilfield stations. Output was not immediately affected there. Rivers state is in the eastern side of the Niger Delta, a vast wetlands region which contains all of Nigeria's petroleum resources. Last month multinationals evacuated hundreds of workers' dependants from the eastern delta after two car bombings in oil company compounds in Rivers state capital Port Harcourt. Foreign companies had already pulled out thousands of workers from the western delta after a wave of militant attacks last February that cut Nigerian output by a fifth. Dozens of foreign oil workers were kidnapped last year by armed groups seeking ransoms, by communities seeking greater benefits from oil companies, and by militants fighting for more autonomy for the impoverished region. Nine foreign oil workers are currently being held by two different groups.
